The Proposal-Telomerase is a ribonucleoprotein responsible for maintenance of telomere length and prevention of chromosomal degradation and recombination. It also repairs DNA strand breaks. We have found that the lens epithelium, including the non-proliferative central epithelium, has telomerase activity and that there is significantly greater activity in LEC from canine cataractous lenses. It is the overall goal of this project to determine the mechanisms by which telomerase activity and telomere length are regulated are regulated in the normal and cataractous lens to determine what essential functions telomerase performs in this tissue. The candidate is in a unique position to examine this pathway because of the ready availability of normal lenses and naturally occurring cataracts in the canine population.